Let's roll up our sleeves and solve this. We have 623 and we're going to multiply it by 491, essentially adding 623 to itself 491 times.
Step 1: 0 + 623 = 623
Step 2: 623 + 623 = 1246
Step 3: 1246 + 623 = 1869
Step 4: 1869 + 623 = 2492
Step 5: 2492 + 623 = 3115
Step 6: 3115 + 623 = 3738
Step 7: 3738 + 623 = 4361
Step 8: 4361 + 623 = 4984
Step 9: 4984 + 623 = 5607
Step 10: 5607 + 623 = 6230
Step 11: 6230 + 623 = 6853
Step 12: 6853 + 623 = 7476
Step 13: 7476 + 623 = 8099
Step 14: 8099 + 623 = 8722
Step 15: 8722 + 623 = 9345
Step 16: 9345 + 623 = 9968
Step 17: 9968 + 623 = 10591
Step 18: 10591 + 623 = 11214
Step 19: 11214 + 623 = 11837
Step 20: 11837 + 623 = 12460
Step 21: 12460 + 623 = 13083
Step 22: 13083 + 623 = 13706
Step 23: 13706 + 623 = 14329
Step 24: 14329 + 623 = 14952
Step 25: 14952 + 623 = 15575
Step 26: 15575 + 623 = 16198
Step 27: 16198 + 623 = 16821
Step 28: 16821 + 623 = 17444
Step 29: 17444 + 623 = 18067
Step 30: 18067 + 623 = 18690
Step 31: 18690 + 623 = 19313
Step 32: 19313 + 623 = 19936
Step 33: 19936 + 623 = 20559
Step 34: 20559 + 623 = 21182
Step 35: 21182 + 623 = 21805
Step 36: 21805 + 623 = 22428
Step 37: 22428 + 623 = 23051
Step 38: 23051 + 623 = 23674
Step 39: 23674 + 623 = 24297
Step 40: 24297 + 623 = 24920
Step 41: 24920 + 623 = 25543
Step 42: 25543 + 623 = 26166
Step 43: 26166 + 623 = 26789
Step 44: 26789 + 623 = 27412
Step 45: 27412 + 623 = 28035
Step 46: 28035 + 623 = 28658
Step 47: 28658 + 623 = 29281
Step 48: 29281 + 623 = 29904
Step 49: 29904 + 623 = 30527
Step 50: 30527 + 623 = 31150
Step 51: 31150 + 623 = 31773
Step 52: 31773 + 623 = 32396
Step 53: 32396 + 623 = 33019
Step 54: 33019 + 623 = 33642
Step 55: 33642 + 623 = 34265
Step 56: 34265 + 623 = 34888
Step 57: 34888 + 623 = 35511
Step 58: 35511 + 623 = 36134
Step 59: 36134 + 623 = 36757
Step 60: 36757 + 623 = 37380
Step 61: 37380 + 623 = 38003
Step 62: 38003 + 623 = 38626
Step 63: 38626 + 623 = 39249
Step 64: 39249 + 623 = 39872
Step 65: 39872 + 623 = 40495
Step 66: 40495 + 623 = 41118
Step 67: 41118 + 623 = 41741
Step 68: 41741 + 623 = 42364
Step 69: 42364 + 623 = 42987
Step 70: 42987 + 623 = 43610
Step 71: 43610 + 623 = 44233
Step 72: 44233 + 623 = 44856
Step 73: 44856 + 623 = 45479
Step 74: 45479 + 623 = 46102
Step 75: 46102 + 623 = 46725
Step 76: 46725 + 623 = 47348
Step 77: 47348 + 623 = 47971
Step 78: 47971 + 623 = 48594
Step 79: 48594 + 623 = 49217
Step 80: 49217 + 623 = 49840
Step 81: 49840 + 623 = 50463
Step 82: 50463 + 623 = 51086
Step 83: 51086 + 623 = 51709
Step 84: 51709 + 623 = 52332
Step 85: 52332 + 623 = 52955
Step 86: 52955 + 623 = 53578
Step 87: 53578 + 623 = 54201
Step 88: 54201 + 623 = 54824
Step 89: 54824 + 623 = 55447
Step 90: 55447 + 623 = 56070
Step 91: 56070 + 623 = 56693
Step 92: 56693 + 623 = 57316
Step 93: 57316 + 623 = 57939
Step 94: 57939 + 623 = 58562
Step 95: 58562 + 623 = 59185
Step 96: 59185 + 623 = 59808
Step 97: 59808 + 623 = 60431
Step 98: 60431 + 623 = 61054
Step 99: 61054 + 623 = 61677
Step 100: 61677 + 623 = 62300
Step 101: 62300 + 623 = 62923
Step 102: 62923 + 623 = 63546
Step 103: 63546 + 623 = 64169
Step 104: 64169 + 623 = 64792
Step 105: 64792 + 623 = 65415
Step 106: 65415 + 623 = 66038
Step 107: 66038 + 623 = 66661
Step 108: 66661 + 623 = 67284
Step 109: 67284 + 623 = 67907
Step 110: 67907 + 623 = 68530
Step 111: 68530 + 623 = 69153
Step 112: 69153 + 623 = 69776
Step 113: 69776 + 623 = 70399
Step 114: 70399 + 623 = 71022
Step 115: 71022 + 623 = 71645
Step 116: 71645 + 623 = 72268
Step 117: 72268 + 623 = 72891
Step 118: 72891 + 623 = 73514
Step 119: 73514 + 623 = 74137
Step 120: 74137 + 623 = 74760
Step 121: 74760 + 623 = 75383
Step 122: 75383 + 623 = 76006
Step 123: 76006 + 623 = 76629
Step 124: 76629 + 623 = 77252
Step 125: 77252 + 623 = 77875
Step 126: 77875 + 623 = 78498
Step 127: 78498 + 623 = 79121
Step 128: 79121 + 623 = 79744
Step 129: 79744 + 623 = 80367
Step 130: 80367 + 623 = 80990
Step 131: 80990 + 623 = 81613
Step 132: 81613 + 623 = 82236
Step 133: 82236 + 623 = 82859
Step 134: 82859 + 623 = 83482
Step 135: 83482 + 623 = 84105
Step 136: 84105 + 623 = 84728
Step 137: 84728 + 623 = 85351
Step 138: 85351 + 623 = 85974
Step 139: 85974 + 623 = 86597
Step 140: 86597 + 623 = 87220
Step 141: 87220 + 623 = 87843
Step 142: 87843 + 623 = 88466
Step 143: 88466 + 623 = 89089
Step 144: 89089 + 623 = 89712
Step 145: 89712 + 623 = 90335
Step 146: 90335 + 623 = 90958
Step 147: 90958 + 623 = 91581
Step 148: 91581 + 623 = 92204
Step 149: 92204 + 623 = 92827
Step 150: 92827 + 623 = 93450
Step 151: 93450 + 623 = 94073
Step 152: 94073 + 623 = 94696
Step 153: 94696 + 623 = 95319
Step 154: 95319 + 623 = 95942
Step 155: 95942 + 623 = 96565
Step 156: 96565 + 623 = 97188
Step 157: 97188 + 623 = 97811
Step 158: 97811 + 623 = 98434
Step 159: 98434 + 623 = 99057
Step 160: 99057 + 623 = 99680
Step 161: 99680 + 623 = 100303
Step 162: 100303 + 623 = 100926
Step 163: 100926 + 623 = 101549
Step 164: 101549 + 623 = 102172
Step 165: 102172 + 623 = 102795
Step 166: 102795 + 623 = 103418
Step 167: 103418 + 623 = 104041
Step 168: 104041 + 623 = 104664
Step 169: 104664 + 623 = 105287
Step 170: 105287 + 623 = 105910
Step 171: 105910 + 623 = 106533
Step 172: 106533 + 623 = 107156
Step 173: 107156 + 623 = 107779
Step 174: 107779 + 623 = 108402
Step 175: 108402 + 623 = 109025
Step 176: 109025 + 623 = 109648
Step 177: 109648 + 623 = 110271
Step 178: 110271 + 623 = 110894
Step 179: 110894 + 623 = 111517
Step 180: 111517 + 623 = 112140
Step 181: 112140 + 623 = 112763
Step 182: 112763 + 623 = 113386
Step 183: 113386 + 623 = 114009
Step 184: 114009 + 623 = 114632
Step 185: 114632 + 623 = 115255
Step 186: 115255 + 623 = 115878
Step 187: 115878 + 623 = 116501
Step 188: 116501 + 623 = 117124
Step 189: 117124 + 623 = 117747
Step 190: 117747 + 623 = 118370
Step 191: 118370 + 623 = 118993
Step 192: 118993 + 623 = 119616
Step 193: 119616 + 623 = 120239
Step 194: 120239 + 623 = 120862
Step 195: 120862 + 623 = 121485
Step 196: 121485 + 623 = 122108
Step 197: 122108 + 623 = 122731
Step 198: 122731 + 623 = 123354
Step 199: 123354 + 623 = 123977
Step 200: 123977 + 623 = 124600
Step 201: 124600 + 623 = 125223
Step 202: 125223 + 623 = 125846
Step 203: 125846 + 623 = 126469
Step 204: 126469 + 623 = 127092
Step 205: 127092 + 623 = 127715
Step 206: 127715 + 623 = 128338
Step 207: 128338 + 623 = 128961
Step 208: 128961 + 623 = 129584
Step 209: 129584 + 623 = 130207
Step 210: 130207 + 623 = 130830
Step 211: 130830 + 623 = 131453
Step 212: 131453 + 623 = 132076
Step 213: 132076 + 623 = 132699
Step 214: 132699 + 623 = 133322
Step 215: 133322 + 623 = 133945
Step 216: 133945 + 623 = 134568
Step 217: 134568 + 623 = 135191
Step 218: 135191 + 623 = 135814
Step 219: 135814 + 623 = 136437
Step 220: 136437 + 623 = 137060
Step 221: 137060 + 623 = 137683
Step 222: 137683 + 623 = 138306
Step 223: 138306 + 623 = 138929
Step 224: 138929 + 623 = 139552
Step 225: 139552 + 623 = 140175
Step 226: 140175 + 623 = 140798
Step 227: 140798 + 623 = 141421
Step 228: 141421 + 623 = 142044
Step 229: 142044 + 623 = 142667
Step 230: 142667 + 623 = 143290
Step 231: 143290 + 623 = 143913
Step 232: 143913 + 623 = 144536
Step 233: 144536 + 623 = 145159
Step 234: 145159 + 623 = 145782
Step 235: 145782 + 623 = 146405
Step 236: 146405 + 623 = 147028
Step 237: 147028 + 623 = 147651
Step 238: 147651 + 623 = 148274
Step 239: 148274 + 623 = 148897
Step 240: 148897 + 623 = 149520
Step 241: 149520 + 623 = 150143
Step 242: 150143 + 623 = 150766
Step 243: 150766 + 623 = 151389
Step 244: 151389 + 623 = 152012
Step 245: 152012 + 623 = 152635
Step 246: 152635 + 623 = 153258
Step 247: 153258 + 623 = 153881
Step 248: 153881 + 623 = 154504
Step 249: 154504 + 623 = 155127
Step 250: 155127 + 623 = 155750
Step 251: 155750 + 623 = 156373
Step 252: 156373 + 623 = 156996
Step 253: 156996 + 623 = 157619
Step 254: 157619 + 623 = 158242
Step 255: 158242 + 623 = 158865
Step 256: 158865 + 623 = 159488
Step 257: 159488 + 623 = 160111
Step 258: 160111 + 623 = 160734
Step 259: 160734 + 623 = 161357
Step 260: 161357 + 623 = 161980
Step 261: 161980 + 623 = 162603
Step 262: 162603 + 623 = 163226
Step 263: 163226 + 623 = 163849
Step 264: 163849 + 623 = 164472
Step 265: 164472 + 623 = 165095
Step 266: 165095 + 623 = 165718
Step 267: 165718 + 623 = 166341
Step 268: 166341 + 623 = 166964
Step 269: 166964 + 623 = 167587
Step 270: 167587 + 623 = 168210
Step 271: 168210 + 623 = 168833
Step 272: 168833 + 623 = 169456
Step 273: 169456 + 623 = 170079
Step 274: 170079 + 623 = 170702
Step 275: 170702 + 623 = 171325
Step 276: 171325 + 623 = 171948
Step 277: 171948 + 623 = 172571
Step 278: 172571 + 623 = 173194
Step 279: 173194 + 623 = 173817
Step 280: 173817 + 623 = 174440
Step 281: 174440 + 623 = 175063
Step 282: 175063 + 623 = 175686
Step 283: 175686 + 623 = 176309
Step 284: 176309 + 623 = 176932
Step 285: 176932 + 623 = 177555
Step 286: 177555 + 623 = 178178
Step 287: 178178 + 623 = 178801
Step 288: 178801 + 623 = 179424
Step 289: 179424 + 623 = 180047
Step 290: 180047 + 623 = 180670
Step 291: 180670 + 623 = 181293
Step 292: 181293 + 623 = 181916
Step 293: 181916 + 623 = 182539
Step 294: 182539 + 623 = 183162
Step 295: 183162 + 623 = 183785
Step 296: 183785 + 623 = 184408
Step 297: 184408 + 623 = 185031
Step 298: 185031 + 623 = 185654
Step 299: 185654 + 623 = 186277
Step 300: 186277 + 623 = 186900
Step 301: 186900 + 623 = 187523
Step 302: 187523 + 623 = 188146
Step 303: 188146 + 623 = 188769
Step 304: 188769 + 623 = 189392
Step 305: 189392 + 623 = 190015
Step 306: 190015 + 623 = 190638
Step 307: 190638 + 623 = 191261
Step 308: 191261 + 623 = 191884
Step 309: 191884 + 623 = 192507
Step 310: 192507 + 623 = 193130
Step 311: 193130 + 623 = 193753
Step 312: 193753 + 623 = 194376
Step 313: 194376 + 623 = 194999
Step 314: 194999 + 623 = 195622
Step 315: 195622 + 623 = 196245
Step 316: 196245 + 623 = 196868
Step 317: 196868 + 623 = 197491
Step 318: 197491 + 623 = 198114
Step 319: 198114 + 623 = 198737
Step 320: 198737 + 623 = 199360
Step 321: 199360 + 623 = 199983
Step 322: 199983 + 623 = 200606
Step 323: 200606 + 623 = 201229
Step 324: 201229 + 623 = 201852
Step 325: 201852 + 623 = 202475
Step 326: 202475 + 623 = 203098
Step 327: 203098 + 623 = 203721
Step 328: 203721 + 623 = 204344
Step 329: 204344 + 623 = 204967
Step 330: 204967 + 623 = 205590
Step 331: 205590 + 623 = 206213
Step 332: 206213 + 623 = 206836
Step 333: 206836 + 623 = 207459
Step 334: 207459 + 623 = 208082
Step 335: 208082 + 623 = 208705
Step 336: 208705 + 623 = 209328
Step 337: 209328 + 623 = 209951
Step 338: 209951 + 623 = 210574
Step 339: 210574 + 623 = 211197
Step 340: 211197 + 623 = 211820
Step 341: 211820 + 623 = 212443
Step 342: 212443 + 623 = 213066
Step 343: 213066 + 623 = 213689
Step 344: 213689 + 623 = 214312
Step 345: 214312 + 623 = 214935
Step 346: 214935 + 623 = 215558
Step 347: 215558 + 623 = 216181
Step 348: 216181 + 623 = 216804
Step 349: 216804 + 623 = 217427
Step 350: 217427 + 623 = 218050
Step 351: 218050 + 623 = 218673
Step 352: 218673 + 623 = 219296
Step 353: 219296 + 623 = 219919
Step 354: 219919 + 623 = 220542
Step 355: 220542 + 623 = 221165
Step 356: 221165 + 623 = 221788
Step 357: 221788 + 623 = 222411
Step 358: 222411 + 623 = 223034
Step 359: 223034 + 623 = 223657
Step 360: 223657 + 623 = 224280
Step 361: 224280 + 623 = 224903
Step 362: 224903 + 623 = 225526
Step 363: 225526 + 623 = 226149
Step 364: 226149 + 623 = 226772
Step 365: 226772 + 623 = 227395
Step 366: 227395 + 623 = 228018
Step 367: 228018 + 623 = 228641
Step 368: 228641 + 623 = 229264
Step 369: 229264 + 623 = 229887
Step 370: 229887 + 623 = 230510
Step 371: 230510 + 623 = 231133
Step 372: 231133 + 623 = 231756
Step 373: 231756 + 623 = 232379
Step 374: 232379 + 623 = 233002
Step 375: 233002 + 623 = 233625
Step 376: 233625 + 623 = 234248
Step 377: 234248 + 623 = 234871
Step 378: 234871 + 623 = 235494
Step 379: 235494 + 623 = 236117
Step 380: 236117 + 623 = 236740
Step 381: 236740 + 623 = 237363
Step 382: 237363 + 623 = 237986
Step 383: 237986 + 623 = 238609
Step 384: 238609 + 623 = 239232
Step 385: 239232 + 623 = 239855
Step 386: 239855 + 623 = 240478
Step 387: 240478 + 623 = 241101
Step 388: 241101 + 623 = 241724
Step 389: 241724 + 623 = 242347
Step 390: 242347 + 623 = 242970
Step 391: 242970 + 623 = 243593
Step 392: 243593 + 623 = 244216
Step 393: 244216 + 623 = 244839
Step 394: 244839 + 623 = 245462
Step 395: 245462 + 623 = 246085
Step 396: 246085 + 623 = 246708
Step 397: 246708 + 623 = 247331
Step 398: 247331 + 623 = 247954
Step 399: 247954 + 623 = 248577
Step 400: 248577 + 623 = 249200
Step 401: 249200 + 623 = 249823
Step 402: 249823 + 623 = 250446
Step 403: 250446 + 623 = 251069
Step 404: 251069 + 623 = 251692
Step 405: 251692 + 623 = 252315
Step 406: 252315 + 623 = 252938
Step 407: 252938 + 623 = 253561
Step 408: 253561 + 623 = 254184
Step 409: 254184 + 623 = 254807
Step 410: 254807 + 623 = 255430
Step 411: 255430 + 623 = 256053
Step 412: 256053 + 623 = 256676
Step 413: 256676 + 623 = 257299
Step 414: 257299 + 623 = 257922
Step 415: 257922 + 623 = 258545
Step 416: 258545 + 623 = 259168
Step 417: 259168 + 623 = 259791
Step 418: 259791 + 623 = 260414
Step 419: 260414 + 623 = 261037
Step 420: 261037 + 623 = 261660
Step 421: 261660 + 623 = 262283
Step 422: 262283 + 623 = 262906
Step 423: 262906 + 623 = 263529
Step 424: 263529 + 623 = 264152
Step 425: 264152 + 623 = 264775
Step 426: 264775 + 623 = 265398
Step 427: 265398 + 623 = 266021
Step 428: 266021 + 623 = 266644
Step 429: 266644 + 623 = 267267
Step 430: 267267 + 623 = 267890
Step 431: 267890 + 623 = 268513
Step 432: 268513 + 623 = 269136
Step 433: 269136 + 623 = 269759
Step 434: 269759 + 623 = 270382
Step 435: 270382 + 623 = 271005
Step 436: 271005 + 623 = 271628
Step 437: 271628 + 623 = 272251
Step 438: 272251 + 623 = 272874
Step 439: 272874 + 623 = 273497
Step 440: 273497 + 623 = 274120
Step 441: 274120 + 623 = 274743
Step 442: 274743 + 623 = 275366
Step 443: 275366 + 623 = 275989
Step 444: 275989 + 623 = 276612
Step 445: 276612 + 623 = 277235
Step 446: 277235 + 623 = 277858
Step 447: 277858 + 623 = 278481
Step 448: 278481 + 623 = 279104
Step 449: 279104 + 623 = 279727
Step 450: 279727 + 623 = 280350
Step 451: 280350 + 623 = 280973
Step 452: 280973 + 623 = 281596
Step 453: 281596 + 623 = 282219
Step 454: 282219 + 623 = 282842
Step 455: 282842 + 623 = 283465
Step 456: 283465 + 623 = 284088
Step 457: 284088 + 623 = 284711
Step 458: 284711 + 623 = 285334
Step 459: 285334 + 623 = 285957
Step 460: 285957 + 623 = 286580
Step 461: 286580 + 623 = 287203
Step 462: 287203 + 623 = 287826
Step 463: 287826 + 623 = 288449
Step 464: 288449 + 623 = 289072
Step 465: 289072 + 623 = 289695
Step 466: 289695 + 623 = 290318
Step 467: 290318 + 623 = 290941
Step 468: 290941 + 623 = 291564
Step 469: 291564 + 623 = 292187
Step 470: 292187 + 623 = 292810
Step 471: 292810 + 623 = 293433
Step 472: 293433 + 623 = 294056
Step 473: 294056 + 623 = 294679
Step 474: 294679 + 623 = 295302
Step 475: 295302 + 623 = 295925
Step 476: 295925 + 623 = 296548
Step 477: 296548 + 623 = 297171
Step 478: 297171 + 623 = 297794
Step 479: 297794 + 623 = 298417
Step 480: 298417 + 623 = 299040
Step 481: 299040 + 623 = 299663
Step 482: 299663 + 623 = 300286
Step 483: 300286 + 623 = 300909
Step 484: 300909 + 623 = 301532
Step 485: 301532 + 623 = 302155
Step 486: 302155 + 623 = 302778
Step 487: 302778 + 623 = 303401
Step 488: 303401 + 623 = 304024
Step 489: 304024 + 623 = 304647
Step 490: 304647 + 623 = 305270
Step 491: 305270 + 623 = 305893

So, 623*491 = 305893